Building a Traditional Wooden Boat #8: Keel, Keelson, Skeg and Sternpost - Part 1

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Blog entry by MattD posted 08-17-2009 06:02 AM 31072 reads 1 time favorited 5 comments Add to Favorites Watch
« Part 7: Stem and Knee - Part 2 Part 8 of Building a Traditional Wooden Boat series Part 9: Attaching Transom, Finding Planking Lumber and Copper Rivets »

This is the construction of the Keel, Keelson, Skeg and Sternpost. These solid oak parts form the bottom backbone of the boat.

I started by cutting out the shape of keel and keelson by transfering the measurements from the lofting. The keel is the thicker piece which be on the very bottom of the boat.

The next step is to put a rolling bevel on the edge of the keelson. The intention is for the bottom planking to fit perfectly into a beveled “notch” that is carved into the keelson and keel. The method I used was to transfer the “bevel” lines from the lofting onto the keelson at each “station” along the length. There are 5 stations along the length of the boat about 21” apart. The following photo shows the lofting for station 1. Each station is a little different.

After the stations are marked, The keelson is put onto the molds and notched at each station to make sure that the planking will fit tightly. I had to make a few minor adjustments.

After each station is notched, I used a batten to draw slightly curved lines on the top and edge of the keelson to “connect” each station. Material between stations is removed with a plane and spokeshave so there is a nice gradual curve between each station. I have not yet cut aft of station 1 or fore of station 4. This will be done later after all the backbone components are fitted together.

At this point, I realize I need a steambox to bend the keelson along the skeg. The book says it can be bent cold (not easily I found), but recommends relieving stress with steam. So I spent a lot of time researching low cost steamboxes that can run indoors and came up with my $75 Eight Foot SteamBox, which I’m really happy with. So the keelson is steamed for a half hour fore of station 4.

Keelson is clamped hot onto the skeg and keel. Bends easy now!

This shows everything assembled in the rear section. The sternpost is the vertical piece that will be connected to the transom.

Here’s a closeup of the skeg section and how all these pieces join. Everything is just test fitted here and needs a little more fitting. The extra length on the keel will be cut off later. The skeg and sternpost and joined with a mortise and tenon that is pinned with 1/4” silicon bronze. The white stuff between the skeg and sternpost is Boatlife Caulk which is like a rubber gasket/bedding compound. All joints will be bedded with this stuff eventually.

Finally, a quick note on the hardware that will be used on this project starting with the next steps. I originally planned to use stainless steel carriage bolts and screws for this project, but decided on 655 Silicon Bronze for below and above the waterline after reading up on the subject. Basically, it’s about twice the cost as stainless, but it’s the standard for wooden boat construction and should last much longer. It also looks great. This alloy is around 97% copper. CCFastners was the most affordable source I could find. They shipped quickly and the hardware is high quality.

Materials List:

Project Materials Summary:

  • Plans and Book: $60
  • Lofting Supplies: $47.88
  • Mold Supplies: $36
  • Strongback Lumber: $33
  • Transom Materials: $22
  • Stem and Knee: $47
  • Keelson, Keel, Skeg and Sternpost: $97
  • Silicon Bronze Hardware: $225

- Total Project Expenses so far: $567.88

Labor Hours Summary:

  • 5/29/09 – 6/8/09: Lofting – 12 Hours
  • 6/14/09 – 6/20/09: Building Molds: 5 Hours
  • 6/25/09 – 6/27/09: Building Strongback: 7.5 Hours
  • 6/30/09 – 7/13/09: Building Transom: 6 Hours
  • 7/14/09 – 7/20/09: Stem Lofting Detail: 3 Hours
  • 7/22/09 – 7/29/09: Stem and Knee Cutout: 4 Hours
  • 7/30/09 – 8/16/09: Keel, Keelson, Skeg and Sternpost: 21 Hours

- Total Project Labor Hours so far: 58.5 Hours
- Time since starting project: 81 days (2 months 20 days)

-- Matt - Syracuse, NY

5 comments so far

View patron's profile


13704 posts in 4119 days

#1 posted 08-17-2009 12:57 PM

looks real nice , matt .

” by guess , or by God “

you will be on ncis ,
before you know it !

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View Steve Dwyer's profile

Steve Dwyer

2 posts in 4017 days

#2 posted 08-19-2009 04:20 AM

Keep up the good work Matt will you be making your first test run on the Liffy or Oneida Lake??

-- Steve, Bernhards Bay, New York

View a1Jim's profile


118066 posts in 4355 days

#3 posted 08-22-2009 06:27 AM

cool blog boats are new to me.


View CaptainSkully's profile


1613 posts in 4336 days

#4 posted 08-24-2009 04:29 PM

Dude! This is one of the coolest blogs on LJ’s. If the 9’ version of this tender will fit on whatever 40’-42’ boat we buy next year, I will be building one. To heck with a Hypalon inflatable. Thanks for all of the feedback on lessons learned along the way. I’m also blown away by the quality of the comments, which shows the true value of LJ’s. Sunshine has classically beautiful lines. As a sailor and a woodworker, this project is imperative. I can’t wait for the next installment!

-- You can't control the wind, but you can trim your sails

View NickCox1's profile


1 post in 3172 days

#5 posted 11-06-2011 01:49 PM

Great info.
I am a novice.
What material did you use for the keel, Keelson and Stern post?

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